This application claims the benefit of priority to PCT International Application no. PCT/EP99/07915, filed Oct. 18, 1999, which claims the benefit of priority to Italian Application no. M198A002258, filed Oct. 20, 1998.
The present invention relates to a gas-insulated switchgear device, particularly for high- and medium-voltage applications, i.e. for voltages greater than 1000V, which comprises particular elements for actuating the disconnection operation.
It is known from the state of the art that electrical operations, both for interruption and for disconnection, in gas-insulated switchgear devices are performed by means of the translatory motion of one or more moving contacts which can couple/uncouple with corresponding fixed contacts. The actuation devices most frequently used in conventional metal-clad devices comprise mechanical or hydraulic actuators which are mechanically connected to a moving contact to be moved by means of suitable actuation means.
The actuation devices of the prior art generally require complicated kinematic systems for transmitting motion to the moving contact. In particular, the disconnection operation requires the coordinated movement of one or more moving contacts so that the opening/closure of the disconnection contacts occurs according to the intended sequence. This usually requires complicated coupling mechanisms and/or complicated actuation and control systems, especially when disconnection occurs on multiple-bar systems.
Because of the mechanical complexity of the actuation means, maintenance is required in order to maintain nominal behavior and therefore ensure repeatability of the operation, compensating for variations due to wear and aging of the system.
Further the large number of parts and component entails an increase in the dimensions and total volume of the gas-insulated device, with a consequent increase ill terms of costs.
The aim of the present invention is to provide a gas-insulated switchgear device in which the disconnection operation occurs in a simple and easily controllable manner.
Within the scope of this aim, an object of the present invention is to provide a gas-insulated switchgear device which has a reduced mechanical complexity. Another object of the present invention is to provide a gas-insulated switchgear device in which the disconnection operation occurs by means of the actuation of a reduced number of mechanical parts.
Another object of the present invention is to provide a gas-insulated switchgear device whose dimensions and space occupation are reduced. Not the last object of the present invention is to provide a gas-insulated switchgear device which is highly reliable, relatively easy to manufacture and at competitive costs.
This aim, these objects and others which will become better apparent hereinafter are achieved by a gas-insulated switchgear device, comprising a casing provided with a first connection terminal and a second connection terminal and containing an interruption unit and a disconnection unit, said disconnection unit comprising a first fixed contact connected to the second connection terminal and a second fixed contact at ground potential, and at least one moving contact which can be coupled to at least one of said fixed contacts and is electrically connected to said interruption unit, characterized in that said moving contact is rigidly fixed to a rotating actuation element and in that the fixed contact that can be coupled to said moving contact lies on the rotation plane of the moving contact.
In the device according to the present invention, the disconnection operation accordinly occurs by means of a rotation of the moving contact about a rotation axis. By virtue of the rotation, the moving contact couples/uncouples with the corresponding fixed contact (or contacts), performing the required disconnection operation. For this purpose, the moving contact and the fixed contact are arranged in such a relative position that the end of the fixed contact that must engage the end of the moving contact lies in the rotation plane traced by said end of the moving contact. For the sake of simplicity, when referring to the relative position of the fixed contact and of the moving contact in the present invention, reference is always made to the relative position of the ends of the fixed contact and of the moving contact that can be coupled thereto.
By selecting appropriate dimensions for the position of the fixed contacts and of the moving contacts in a longitudinal direction with respect to the rotation axis of the rotating actuation element and by appropriately varying their relative angular position with respect to the rotation axis, it is possible to minimize the volume and space required by the disconnection unit, and therefore by the entire device, while maintaining easy execution of the disconnection operation.